The mind is what it thinks. To make it true, think true. ~Nisargadatta Maharaj

No problem can withstand the assault of sustained thinking. ~Voltaire

[B]elief is the antithesis to thinking. A refusal to come to an unjustified conclusion is an element of an honest man's religion. To him the call to blind faith is really a call to barbarism and slavery. In being asked to believe without evidence, he is being asked to abdicate his integrity. Freedom of speech and freedom of action are meaningless without freedom to think. And there is no freedom of thought without doubt. The civilized man has a moral obligation to be skeptical, to demand the credentials of all statements that claim to be facts. An honorable man will not be bullied by a hypothesis. For in the last analysis, all tyranny rests on fraud, on getting someone to accept false assumptions, and any man who for one moment abandons or suspends the questioning spirit has for that moment betrayed humanity. ~Bergen Evans, The Natural History of Nonsense, 1946 ["This book.... is a study in the paleontology of delusion. It is an antibody for all who are allergic to Stardust. It is a manual of chiropody for feet of clay." B.E. —tεᖇᖇ¡·g]

People demand freedom of speech as a compensation for the freedom of thought which they seldom use. ~Søren Kierkegaard

Never be afraid to sit awhile and think. ~Lorraine Hansberry, A Raisin in the Sun

...men worn by the unequal irritations of too much thinking... ~Thomas De Quincey (1785–1859), "Temperance Movement"

We Americans... think too much, and too morbidly, — brood, meditate, become sickly with our own pallid fancies, allowing them to swarm upon us by night and by day. It will, of course, sound strange in the ears of many to say so, but we are fain to proclaim over and over again, in our loudest and most emphatic tones, We are too intellectual a race. To the brain parts of our structure we draw off much that should be devoted to the body, the muscles — neglecting what all men first require, to be fine animals. We suppose we shall excite some disdain by such remarks, but they include undoubted truths necessary to be told. ~Mose Velsor (Walt Whitman), "Manly Health and Training" (Too Much Brain Action and Fretting), New York Atlas, 1858 December 19th

Maybe I think too much for my own good
Some people say so
Other people say, "No no
That fact is
You don't think as much as you could"
~Paul Simon, "Think Too Much (a)," 1982 ♫

No matter where you go or what you do, you live your entire life within the confines of your head. ~Terry Josephson

You and I are not what we eat; we are what we think. ~Walter Anderson, The Confidence Course, 1997

Invest a few moments in thinking. It will pay good interest. ~Author Unknown

Not all day long can I contemplate, for time is passing, and I, too, must live. ~Muriel Strode (1875–1964), My Little Book of Prayer, 1904

Some people get lost in thought because it's such unfamiliar territory. ~G. Behn

As tall trees of the forest are the first to be smitten by the storm and shattered by the thunderbolt, so men of advanced thought are the first assailed by the tempests of popular indignation. ~James Lendall Basford (1845–1915), Sparks from the Philosopher's Stone, 1882

Thinking is like loving and dying. Each of us must do it for himself. ~Josiah Royce

It is well for people who think, to change their minds occasionally in order to keep them clean. ~Luther Burbank

There are thoughts which appear not to have come from the senses, but rather to have been forced through the skull. ~James Lendall Basford (1845–1915), Sparks from the Philosopher's Stone, 1882

Physiological response to thinking and to pain is the same; and man is not given to hurting himself. ~Martin H. Fischer (1879–1962)

Deep thinkers often lose two good thoughts by coming to the surface to record one. ~James Lendall Basford (1845–1915), Sparks from the Philosopher's Stone, 1882

We spend our days in deliberating, and we end them without coming to any resolve. ~L'Estrange, quoted in Edge-Tools of Speech by Maturin M. Ballou, 1886

Our job is not to make up anybody's mind, but to open minds and to make the agony of the decision-making so intense you can escape only by thinking. ~Author Unknown

Thinking in its lower grades is comparable to paper money, and in its higher forms it is a kind of poetry. ~Havelock Ellis, The Dance of Life, 1923

Reason ripens not in the torrid zone of passion, or amidst the frosts of bigotry. ~James Lendall Basford (1845–1915), Sparks from the Philosopher's Stone, 1882

The average man never really thinks from end to end of his life. The mental activity of such people is only a mouthing of clichés. ~H.L. Mencken, Prejudices, 1925

Few people think more than two or three times a year. I have made an international reputation for myself by thinking once or twice a week. ~George Bernard Shaw, quoted in Reader's Digest, May 1933 (Thanks, Garson O'Toole! quoteinvestigator.com/2014/02/20/shaw-think)

...the thoughtful excitement of lonely rambles, of gardening, and of other like occupations, where the mind has leisure to must during the healthful activity of the body, with the fresh and wakeful breezes blowing round it... ~Augustus William Hare and Julius Charles Hare, Guesses at Truth, by Two Brothers, 1827

Belief is when someone else does the thinking. ~Buckminster Fuller, 1972

Irons rusts from disuse, stagnant water loses its purity and in cold weather becomes frozen; even so does inaction sap the vigor of the mind. ~Leonardo da Vinci, Notebooks, 1508

A sect or party is an elegant incognito devised to save a man from the vexation of thinking. ~Ralph Waldo Emerson

One morning, when it must be acknowledged that Helen had been sitting too long in the same position with her head leaning on her hand, Miss Clarendon, in her abrupt voice, asked, "How much longer, Helen, do you intend to sit there, doing only what is the worst thing in the world for you—thinking?"
Helen started, and said she feared she had been sitting too long idle. ~Maria Edgeworth (1768–1849), Helen, 1834

Nothing is more conducive to peace of mind than not having any opinion at all. ~G.C. Lichtenberg

The world we have created is a product of our thinking; it cannot be changed without changing our thinking. ~Albert Einstein

Brain, n. An apparatus with which we think that we think. ~Ambrose Bierce, The Devil's Dictionary

At a certain age some people's minds close up; they live on their intellectual fat. ~William Lyon Phelps

All sorts of reflections of this nature passed through my mind—for as I grow older I regret to say that a detestable habit of thinking seems to be getting a hold of me... ~H. Rider Haggard, King Solomon's Mines

Thoughts are like an open ocean, they can either move you forward within its waves, or sink you under deep into its abyss. ~Anthony Liccione

[H]is habit of thought had been formed in the days of the epic struggle between physics and metaphysics. ~Edith Wharton, "The Eyes," Tales of Men and Ghosts, 1910

It's crazy how you can get yourself in a mess sometimes and not even be able to think about it with any sense and yet not be able to think about anything else. ~Stanley Kubrick

We are dying from overthinking. We are slowly killing ourselves by thinking about everything. Think. Think. Think. You can never trust the human mind anyway. It's a death trap. ~Anthony Hopkins

One cannot think crooked and walk straight. ~Author Unknown

Thought is the wind, knowledge the sail, and mankind the vessel. ~Augustus William Hare and Julius Charles Hare, Guesses at Truth, by Two Brothers, 1827

No amount of energy will take the place of thought. A strenuous life with its eyes shut is a kind of wild insanity. ~Henry Van Dyke

A superficial thinker deals in the news of the day; a deep one in the news of ages. ~James Lendall Basford (1845–1915), Sparks from the Philosopher's Stone, 1882

Tell your friends not to think aloud
Until they swallow.
~Nickelback, "Leader of Men," The State

Believing is easier than thinking. Hence so many more believers than thinkers. ~Bruce Calvert

A man is not idle because he is absorbed in thought. There is a visible labor and there is an invisible labor. ~Victor Hugo

Practical gentlemen hate uncertainty, balancing of probabilities, skepticism or approximation. They have a number of bitterly satirical comments on persons whose minds are so open that their brains fall out. They are bent on getting to a conclusion. ~Max Radin, 1937

Sometimes I think and other times I am. ~Paul Valéry, Variété: Cantiques spirituels, 1924

Few minds wear out; more rust out. ~Christian N. Bovee

From restless thoughts, that, like a deadly swarm
Of hornets arm'd, no sooner found alone,
But rush upon me thronging.
~John Milton

What a blessing it is to be alone with your thoughts when so many are alone with their inability to think. ~Robert Brault, rbrault.blogspot.com

We use 10% of our brains. Imagine how much we could accomplish if we used the other 60%. ~Ellen Degeneres

A just thinker will allow full swing to his scepticism. I dip my pen in the blackest ink, because I am not afraid of falling into my inkpot.... We are of different opinions at different hours, but we always may be said to be at heart on the side of truth. ~Ralph Waldo Emerson, "Worship," The Conduct of Life, 1860

Opinion is that exercise of the human will which helps us to make a decision without information. ~John Erskine

Some people do not become thinkers simply because their memories are too good. ~Friedrich Wilhelm Nietzsche

A man's spirit is like the boundless space around him, and his thoughts are the stars within it. ~James Lendall Basford (1845–1915), Seven Seventy Seven Sensations, 1897

If a man's stomach has been filled by eating greens and other vegetables, although the most precious dainties with exquisite tastes should be given him, he cannot swallow them, he must first get rid of a few portions of the greens; so in reading, the same is true of the mixed thoughts which distract the mind, which are about the dusty affairs of a vulgar world. ~Robert Morrison, quoted in The Middle Kingdom by Samuel Wells Williams

Men can live without air a few minutes, without water for about two weeks, without food for about two months — and without a new thought for years on end. ~Kent Ruth

There are times in human experience when the machinery of thought runs so quietly that only the results indicate its motion. ~James Lendall Basford (1845–1915), Sparks from the Philosopher's Stone, 1882

The thoughts that come often unsought, and, as it were, drop into the mind, are commonly the most valuable of any we have. ~John Locke, 16 May 1699

Men who borrow their opinions can never repay their debts. ~George Savile, Marquess de Halifax, Miscellaneous Thoughts and Reflections

A lawyer's brief will be brief, before a freethinker thinks freely. ~Augustus William Hare and Julius Charles Hare, Guesses at Truth, by Two Brothers, 1827

Chi Wen Tzu always thought three times before taking action. Twice would have been quite enough. ~Confucius, Analects

Impartial observers from other planets would consider ours an utterly bizarre enclave if it were populated by birds, defined as flying animals, that nevertheless rarely or never actually flew. They would also be perplexed if they encountered in our seas, lakes, rivers, and ponds, creatures defined as swimmers that never did any swimming. But they would be even more surprised to encounter a species defined as a thinking animal if, in fact, the creature very rarely indulged in actual thinking. ~Steve Allen

What luck for rulers, that men do not think. ~Adolph Hitler

Doubt is not a pleasant state of mind, but certainty is absurd. ~Voltaire, 1767

Men fear thought as they fear nothing else on earth, more than ruin, more even than death. Thought is subversive and revolutionary, destructive and terrible, thought is merciless to privilege, established institutions, and comfortable habit. Thought looks into the pit of hell and is not afraid. Thought is great and swift and free, the light of the world, and the chief glory of man. ~Bertrand Russell

[Thinking is] what a great many people think they are doing when they are merely rearranging their prejudices. ~William James

For those who do not think, it is best at least to rearrange their prejudices once in a while. ~Luther Burbank

How wonderful that we have met with a paradox. Now we have some hope of making progress. ~Niels Bohr

You cannot plough a field by turning it over in your mind. ~Author Unknown

He who will not reason is a bigot; he who cannot is a fool; and he who dares not is a slave. ~William Drummond, Academical Questions

Ours is the age which is proud of machines that think and suspicious of men who try to. ~Howard Mumford Jones